Picking a CC holster is a personal choice just like buying a gun. What works well for someone won't for another.
Where and how you carry depends on variables such as how you dress, type/size of firearm you are trying to conceal, what you are doing while carrying (active or relaxed), and body size/type.
Someone wearing a suit jacket all day every day will be able to conceal a larger weapon than the guy wearing a polo and jeans.
I carry all the time, from business attire to weekend cargo's and a T-shirt, so I use different methods and carry different firearms that fit the occasion.
It is trial and error mostly, but I will give you a bit of advice that is commonly overlooked... Buy a quality gun belt. Many CCer's purchase a nice pistol and holster and try to carry with a common pants belt.
A cheap dress belt isn't meant to support the weight of a firearm. A gun will conceal better with an inexpensive holster on a good gun belt than a top notch holster will on a single thickness pants belt.
I have worn many different holster manufacture's belts over the years and prefer the High Noon Holster Co belt. It is two layers of leather with a polymer insert sandwiched in between. Very stiff and able to support the heaviest gun.
For a more casual look with cargo shorts I use a Wilderness Frequent Flyer's 5 stitch belt with polymer insert. I have found myself wearing this belt more and more lately; very good design, especially with Kydex gear.
I prefer 1 1/2" thick belts and have found that more narrow belts will allow the grip to twist out and away from your body, especially the thicker double stack models. Barrel length isn't so much of a concealment issue for me it's the gun's grip that tends to give it away.
